Water quality hardness detection device

Abstract

This application provides a water hardness testing device, comprising: an electrolysis system including an electrolysis chamber, a limiter for fixing an anode being provided at one end of the electrolysis chamber, and a seat for fixing a cathode being provided at the other end of the electrolysis chamber, the cathode being arranged around the anode, and an electrode separator being provided between the cathode and the anode; a detection system including a detection chamber in fluid communication with the electrolysis system, the detection chamber having a TDS probe for detecting the TDS value of the water to be tested within the detection chamber; before the electrolysis system electrolyzes the water to be tested, the detection system performs a first measurement to obtain the TDS value of the water to be tested before electrolysis, and after the electrolysis system electrolyzes the water to be tested, the detection system performs a second measurement to obtain the TDS value of the water to be tested after electrolysis; and a calculation module, which calculates the electrolysis TDS change rate based on the TDS values ​​of the water to be tested before and after electrolysis, and determines the water hardness of the water to be tested based on a pre-determined correlation between water hardness and the electrolysis TDS change rate.

Description

Technical Field

[0001] This invention relates to the field of water quality testing technology, and in particular to a water hardness testing device. Background Technology

[0002] A water softener softens hard water by using an ion exchange resin. Specifically, it softens the calcium in the incoming water. 2+ / Mg 2 + It is chelated and fixed on the ion exchange resin, while the original Na on the resin is fixed. + Desorption is used to achieve a soft water effect.

[0003] Besides parameters such as water flow rate, salinity, and regeneration cycle, water hardness is another more scientifically important parameter for evaluating the softening effect of a water softener. Users can intuitively understand the softening effect by checking the water hardness. For example, if the hardness of the softened water is greater than 30 mg / L (calculated as CaCO3) or higher, it indicates that the resin has become saturated and needs regeneration to restore its softening performance. Simultaneously, the hardness of the incoming water needs to be calibrated to further determine the operating status of the water softener.

[0004] Current water hardness testing technologies suffer from drawbacks such as the need for chemical reagents, large size, high cost, and frequent maintenance, hindering their widespread application in household or commercial water softening systems. Therefore, there is an urgent need for a miniaturized device that can conveniently and quickly test water hardness. Summary of the Invention

[0005] The main objective of this invention is to provide a water hardness testing device to solve the problem of the lack of effective and reliable online water hardness testing technology in the prior art.

[0006] According to an embodiment of the present invention, a water hardness testing device is provided, comprising:

[0007] An electrolysis system includes a sealed electrolysis chamber, one end of which is provided with a limiter for fixing an anode, and the other end of which is provided with a base for fixing a cathode, wherein the cathode is arranged around the anode, and an electrode separator is provided between the cathode and the anode.

[0008] The detection system includes a detection chamber in fluid communication with the electrolysis system, and the detection chamber has a TDS probe for detecting the TDS value of the water to be tested in the detection chamber;

[0009] Specifically, before the electrolysis system electrolyzes the water to be tested, the detection system performs a first measurement to obtain the TDS value of the water to be tested before electrolysis; after the electrolysis system electrolyzes the water to be tested, the detection system performs a second measurement to obtain the TDS value of the water to be tested after electrolysis.

[0010] The calculation module is used to obtain the electrolysis TDS change rate based on the TDS values ​​of the water before and after electrolysis, and to determine the water hardness of the water to be tested based on the pre-determined correlation between water hardness and the water electrolysis TDS change rate.

[0011] According to an embodiment of the present invention, a water hardness testing device is also provided, comprising:

[0012] An electrolysis system includes a sealed electrolysis chamber, one end of which is provided with a limiter for fixing an anode, and the other end of which is provided with a base for fixing a cathode, wherein the cathode is arranged around the anode, and an electrode separator is provided between the cathode and the anode.

[0013] The detection system includes a detection chamber in fluid communication with the electrolysis system, and the detection chamber has a TDS probe for detecting the TDS value of the water to be tested in the detection chamber;

[0014] A voltage control module is used to apply a positive voltage to the electrode to preactivate the electrode;

[0015] The electrolysis system performs a first electrolysis treatment on the water to be tested before pre-activating the electrode, and a second electrolysis treatment on the water to be tested after pre-activating the electrode; the detection system performs a first measurement on the water to be tested to obtain a first TDS value before the first electrolysis treatment, a second measurement on the water to be tested to obtain a second TDS value after the first electrolysis treatment, a third measurement on the water to be tested to obtain a third TDS value before the second electrolysis treatment, and a fourth measurement on the water to be tested to obtain a fourth TDS value after the second electrolysis treatment.

[0016] The calculation module obtains the first electrolytic TDS change rate of the water to be tested based on the first TDS value and the second TDS value; obtains the second electrolytic TDS change rate of the water to be tested based on the third TDS value and the fourth TDS value; and obtains the difference between the change rates based on the first electrolytic TDS change rate and the second electrolytic TDS change rate.

[0017] The calculation module further determines the standard water hardness based on the pre-measured correlation between water hardness and the change rate of TDS in the second electrolysis; determines the floating water hardness based on the pre-measured correlation between the difference between water hardness and the change rate; and determines the water hardness of the water to be tested based on the standard water hardness and the floating water hardness.

[0018] According to the technical solution of the present invention, the water hardness of the water sample to be tested is determined based on the TDS difference before and after electrolysis. This solution does not use chemical reagents and can measure the water hardness of raw water and softened water online. It has the advantages of small size, simple maintenance and low detection cost. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0020] Figure 1A This is a perspective view of a water hardness testing device according to an embodiment of the present invention;

[0021] Figure 1B This is a front view of a water hardness testing device according to an embodiment of the present invention;

[0022] Figure 2 This is a structural block diagram of a water hardness testing device according to an embodiment of the present invention;

[0023] Figures 3 to 6 These are schematic diagrams of the water inlet system, electrolysis system, detection system, and drainage system of the water hardness testing device according to an embodiment of the present invention.

[0024] Figure 7 This is a flowchart of the detection process of a basic water hardness testing device according to an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram illustrating the functional relationship between the rate of change of TDS and the water quality-related factor W according to an embodiment of the present invention.

[0026] Figure 9 This is a schematic diagram illustrating the linear relationship between the pre-exponential factor A and TDS0 according to an embodiment of the present invention;

[0027] Figure 10 W and ΔTDS at different temperatures according to embodiments of the present invention 15 A diagram illustrating the reciprocal relationship of / 15;

[0028] Figure 11 This is a schematic diagram comparing two water hardness calculation results according to an embodiment of the present invention;

[0029] Figure 12 This is a flowchart of the detection process of an advanced water hardness detection device according to an embodiment of the present invention;

[0030] Figure 13 It is Δ(ΔTDS) according to an embodiment of the present invention 15A schematic diagram of the linear relationship between / 15) and ΔH;

[0031] Figure 14 This is a comparative schematic diagram of three water hardness calculation results according to an embodiment of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] According to an embodiment of the present invention, a water hardness testing device is provided. This device can detect the water hardness of municipal tap water (raw water) and softened water (soft water) from a water softener online. It is particularly suitable for situations where the ratio of water hardness (calculated as CaCO3) to total dissolved solids (TDS) is between 50% and 60%. The device measures the change rate of TDS before and after water sample electrolysis (denoted as ΔTDS). n The relationship between / n (where n represents the electrolysis time) and water hardness is used to calculate (standard) water hardness. For clarity, the device in this embodiment can be referred to as a basic water hardness testing device.

[0034] refer to Figure 1A , Figure 1B and Figure 2 The water to be tested (raw water / softened water) enters the water hardness testing device 20 through the bypass valve 10. The water hardness testing device 20 includes, in sequence according to the water flow direction: water inlet system 30, electrolysis system 40, detection system 50, drainage system 60, voltage control module 70 and calculation module 80.

[0035] The bypass valve 10 can be part of the water inlet system 30 or part of the water circuit of the water softener. In practical applications, softened water from the water softener can enter the electrolysis system 40 through at least one of the two inlet pipes located above the bypass valve 10, while municipal tap water (raw water) can enter the electrolysis system 40 through at least one of the two inlet pipes located before the bypass valve 10. Of course, the inlet water circuits for raw water and softened water can also be interchanged before entering the electrolysis system 40, and this application does not impose any restrictions.

[0036] Reference Figure 3The water inlet system 30 includes two inlet pipes 31 and an inlet system solenoid valve 32. The inlet pipes 31 serve as the water inlet and are in fluid communication with the bypass valve 10. Under the control of the inlet solenoid valve 32, raw water / softened water enters the electrolysis system 40 through at least one of the two inlet pipes 31. It should be noted that in other embodiments, the water inlet system 30 may also include one inlet pipe and one solenoid valve; this application does not impose any limitations.

[0037] Reference Figure 4 The electrolysis system 40 is mainly used for electrolyzing raw water / softened water. The electrolysis system 40 mainly includes a sealed electrolysis chamber 41. The electrolysis chamber 41 can be a cylindrical chamber extending horizontally. Passages connecting to the water inlet system 30 can be provided above and in front of the chamber. Raw water / softened water enters the electrolysis chamber 41 under the control of the water inlet system solenoid valve 32. A passage connecting to the detection system 50 is provided below the electrolysis chamber 41. The cylindrical chamber also has eaves extending out of the shell on both sides, with protective covers to protect the electrode terminals and provide waterproofing. An overflow channel 42 connecting the electrolysis chamber 41 is also provided above the electrolysis system 40. The inner wall of the cylindrical electrolysis chamber 42 has a draft angle to facilitate the discharge of gas generated during electrolysis or excess water through the overflow channel 44. It should be noted that in other embodiments, the electrolysis chamber can also be square or other shapes, as long as it provides a sealed electrolysis space.

[0038] Continue to refer to Figure 4 The electrolysis chamber 41 specifically includes an anode 43 and a cathode 44 surrounding the anode. The anode 43 can be a cylindrical graphite rod or other conductive material. The cathode 44 can be a cylindrical metal mesh tube, which can be any conductive metal. The mesh density can be adjusted arbitrarily, and its size can be set arbitrarily within the size range of the electrolysis chamber. The anode 43 and cathode 44 extend axially within the electrolysis chamber 41. The anode 43 can be positioned in the middle of the electrolysis chamber 41, and the cathode 44 is essentially positioned around the outside of the anode 43. A limiter 45 is fixedly installed at one end of the electrolysis chamber 41, and a seat 46 is fixedly installed at the other end. The limiter 45 is used to limit and fix the position of the anode 43. The anode 43 can be fastened to the limiter 45 with a nut. A wire extends from the end of the anode 43 for power connection to the anode. The limiter 45 is a sealing limiter, and an O-ring is provided between it and the inner wall of the electrolysis chamber 41 to prevent leakage. The base 46, also known as the seat, can be welded to the cathode 44. The terminals of the base 46 are threaded and secured to the power supply wiring with nuts. The nuts have tabs, allowing the power supply to be connected to the anode via plug-in wires. An O-ring is provided between the base 48 and the inner wall of the electrolysis chamber 42 to prevent leakage. Additionally, an electrode separator 47 is provided between the cathode 44 and the anode 43 to isolate them.

[0039] refer to Figure 5 The detection system 50 is mainly responsible for TDS testing of raw water / softened water. Specifically, the detection system 50 includes a detection chamber 51 and a detection system solenoid valve 52. The detection chamber 51 is in fluid communication with the electrolysis chamber 41. Under the control of the solenoid valve 52, water from the electrolysis chamber 41 is introduced into the detection chamber 51. It should be noted that the water from the electrolysis chamber 41 includes water before electrolysis (i.e., water that has not undergone electrolysis) or water after electrolysis. In this embodiment, the detection chamber 51 can be a cuboid space to receive water from the electrolysis chamber 41. The detection chamber 51 has an interface at its bottom to connect to a TDS probe 53 for detecting the TDS value of the raw water / softened water in the detection chamber 51. An overflow channel can also be provided at the top of the detection chamber 51 to prevent excessive water sample from entering and damaging the detection chamber if the solenoid valve fails. In addition, the bottom of the detection chamber 51 can adopt a funnel-shaped design to facilitate the smooth discharge of the water sample after testing and minimize the impact of water accumulation in the chamber on the test results. It should be noted that in other embodiments, the internal space of the detection chamber can also be other three-dimensional shapes, and its volume can also vary, but it is necessary to ensure that there is sufficient water sample to immerse the TDS probe to ensure the accuracy of the measurement.

[0040] refer to Figure 6 The drainage system 60 includes a drainage passage communicating with the detection chamber 52. This drainage passage has a drainage system solenoid valve 61, and downstream of the solenoid valve 61 is a water outlet 62. Under the control of the solenoid valve 61, water samples are discharged through the water outlet 62. The water outlet 62 can be directly connected to the user's drainage pipeline or via an extension pipe. The drainage passage may also have an interface that can be connected to the overflow channels of the electrolysis system and the detection system as needed to facilitate drainage from these two chambers.

[0041] It should be noted that the water inlet system, electrolysis system, detection system, and drainage system described above in this application are not limited to the aforementioned arrangement. For example, the electrolysis system can also be installed vertically, with the water inlet system introducing the water sample to be tested from the bottom of the electrolysis system, exiting from the top of the electrolysis system, and then entering the detection system, followed by the drainage system. Regardless of the internal configuration of the hardness testing device, it is always necessary to fix the above four systems and their upstream and downstream relationships to achieve complete hardness testing functionality.

[0042] According to an embodiment of this application, a voltage control module 70 is used to apply a positive voltage or a reverse voltage to the electrode, and for the duration of application. When a reverse voltage is applied, it is used to clean the electrode surface. When a positive voltage is applied (for a longer time, such as 60 seconds), it is used to pre-activate the electrode. When a positive voltage is applied (for a shorter time, such as 15 seconds), it is used for water electrolysis.

[0043] In this process, before the electrolysis system 50 electrolyzes the water to be tested, the detection system 40 performs a first measurement to obtain the TDS value of the water to be tested before electrolysis. After the electrolysis system 50 electrolyzes the water to be tested, the detection system 40 performs a second measurement to obtain the TDS value of the water to be tested after electrolysis.

[0044] The calculation module 80 is used to obtain the electrolysis TDS change rate based on the TDS values ​​of the water before and after electrolysis, and to determine the water hardness of the water to be tested based on the pre-determined correlation between water hardness and the water electrolysis TDS change rate.

[0045] In other embodiments of this application, the solenoid valves of the inlet system, the detection system, and the drainage system can also be replaced by small water pumps, stepper motor valves, etc., to control the on / off state of the inlet water flow. During raw water / soft water hardness testing, all functions of the solenoid valves (including the replaceable stepper motor valves and small water pumps), including power supply, on / off action, voltage application / disconnection, TDS probe power supply, signal acquisition, and final water hardness calculation, can be implemented by the electronic control program integrated on the circuit board 90.

[0046] The following is combined Figure 7 The working process of the basic water hardness testing device is described in detail. In this embodiment, the electrolysis time in the electrolysis chamber is 15 seconds. Extensive experiments have proven that a 15-second electrolysis time can accurately and quickly measure the hardness of a water sample. The following explanation uses an electrolysis time of 15 seconds (n=15) as an example. (Reference) Figure 7 Specifically, it includes:

[0047] The first step is to open all solenoid valves (including the inlet solenoid valve, the detection system solenoid valve, and the drain system solenoid valve) to allow the water sample to be tested to flow completely through all passages and chambers (including the electrolysis chamber and the detection chamber) and perform a flushing operation (for example, for 25 seconds) to prevent any impurities that may be present in the device from contaminating the test results.

[0048] The second step is to rinse thoroughly, then close the solenoid valves of the detection system and the drainage system, allowing the water sample to fill and permeate the electrolysis chamber (time 2 is, for example, 5 seconds).

[0049] The third step involves applying a reverse voltage (e.g., 12 V) to the electrodes. At this point, the graphite rod acts as the cathode, and the metal mesh tube as the anode, with the aim of cleaning the electrode surface (time 3, e.g., 30 s).

[0050] Fourth step: Open the solenoid valve of the detection system and the solenoid valve of the drainage system to discharge the wastewater generated in the third step (time 4, for example, 5 seconds).

[0051] Fifth step, repeat the first step, that is, open all solenoid valves to allow the water sample to be tested to flow completely through all passages and chambers, and perform a flushing operation (time 1, for example, 25 s) to prevent impurities that may exist in the device from contaminating the test results.

[0052] Step 6: Repeat step 2, that is, after rinsing thoroughly, close the solenoid valves of the detection system and the drainage system to allow the water sample to be tested to fill and fill the electrolysis chamber (time 2 is, for example, 5 s).

[0053] Step 7: Apply a positive voltage (e.g., 12 V) to the electrodes. At this time, the graphite rod is the anode and the metal mesh tube is the cathode, the purpose of which is to pre-activate the electrodes (time 5, e.g., 60 s).

[0054] Step 8: Repeat step 4, that is, open the solenoid valve of the detection system and the solenoid valve of the drainage system to discharge the wastewater generated in the previous step (time 4 is, for example, 5 seconds).

[0055] Step 9: Repeat step 1, that is, open all solenoid valves to allow the water sample to be tested to flow completely through all passages and chambers, and perform a flushing operation (time 1, for example, 25 s) to prevent any impurities in the module from contaminating the test results.

[0056] Step 10: Repeat step 2, that is, after rinsing thoroughly, close the solenoid valves of the detection system and the drainage system to allow the water sample to fill and fill the electrolysis chamber (time 2 is, for example, 5 s).

[0057] Step 11: Open the solenoid valve of the detection system to collect water into the detection chamber until the preset volume is reached (time 6, for example, 4 seconds).

[0058] Step 12: Close all solenoid valves, power on the TDS probe and collect TDS data, denoted as TDS0 (time 7, for example, 30 s).

[0059] Step 13: Open the solenoid valves of the water inlet system and the drainage system to replenish water to the electrolysis chamber while draining the water sample from the detection chamber (time 2, for example, 4 seconds).

[0060] Step 14: After the electrolysis chamber is filled, a positive electrolysis voltage is applied to the electrodes to electrolyze the water to be tested (e.g., electrolysis voltage 12V, time 8 for example 15 s).

[0061] Step 15: Repeat step 11, that is, open the solenoid valve of the detection system to collect water into the detection chamber until the preset volume is reached (time 6, for example, 4 seconds).

[0062] Step sixteen: Repeat step twelve, that is, close all solenoid valves, energize the TDS probe and collect TDS data, which is recorded as TDS. 15 (Time 7 is, for example, 30 seconds).

[0063] Step 17: Close the inlet solenoid valve and open the detection system and drainage system solenoid valves to empty all passages and chambers of the device (time 9, for example, 15 seconds).

[0064] Finally, close all solenoid valves to end the process.

[0065] In the above process, the duration of each solenoid valve operation, such as the reversal or electrolysis time and the TDS probe detection time, are preferred implementation values ​​of this application. In reality, different electrolysis chamber volumes and shapes will result in different filling times for the electrolysis chamber and detection chamber; different electrode configurations will also lead to different electrolysis voltages and electrolysis times; and different requirements for TDS signal accuracy will result in different TDS signal collection times. Therefore, it is not necessary to be limited to the operating parameters such as electrolysis voltage and solenoid valve on / off time mentioned in the above process; adjustments can be made according to the specific detection device.

[0066] This application is based on TDS0 and TDS 15 To determine the hardness of a water sample by measuring the difference between the TDS and the water hardness, a mathematical relationship needs to be established between this difference and the water hardness. This application uses the rate of change of TDS before and after electrolysis, i.e., (TDS0 - TDS2). 15 ) / 15 (denoted as ΔTDS) 15 / 15) serves as a bridge to establish this mathematical relationship.

[0067] refer to Figure 8 If the TDS and hardness of the water to be tested are kept constant, and only the pH value of the water to be tested is changed, ΔTDS 15 / 15 has a reciprocal relationship with the water quality-related factor (W) (where different colors represent different water qualities), as shown in the following formula:

[0068] W=A×(ΔTDS 15 / 15) -1

[0069] Among them, when TDS0 varies in the range of 100-700 ppm, the standard hardness varies in the range of 50-460 ppm, and ΔTDS 15 When / 15 varies in the range of 0-3, the pre-exponential factor (A) varies in the range of 6-30, while W varies in the range of 0-50.

[0070] refer to Figure 9 Through extensive simulated water experiments, it was concluded that there is a clear linear relationship between the pre-exponential factor A and TDS0, as shown in the following equation:

[0071] A = a × TDS0 - b, where the value of a is between 0.044 and 0.045, and the value of b is between 2.40 and 2.44.

[0072] Based on experimental data from a large number of simulated water samples, the hardness (H) and ΔTDS of the water sample to be tested can be determined. 15 The relationship between / 15 is as follows:

[0073] H=A×(ΔTDS 15 / 15) -1 ×ΔTDS 15 =W×ΔTDS 15

[0074] It can be seen that the above formula does not contain a temperature term. This is because, under the same TDS0 and typical water temperatures (7-40°C), the form of the reciprocal function does not change significantly. (Reference) Figure 10 ΔTDS 15 The functional relationship between / 15 and W, as well as the relationship between A and TDS0, will change with the construction of the electrolysis chamber and the change in the sampling amount in the detection chamber, and need not be limited to the existing reciprocal function relationship and linear relationship.

[0075] The following example uses municipal tap water to calculate the hardness of a water sample using the water hardness testing device based on this application. Figure 11 As shown, the blue bar on the left represents the actual value measured by titration, and the yellow bar on the right represents the predicted value calculated using the water hardness testing device based on this application. For the municipal tap water in locations A1, A2, B1, B2, and B3, the water hardness of the municipal tap water was calculated using the water hardness testing device based on this application. The specific calculation process is as follows:

[0076] Location A, 1: TDS0 = 428 ppm, TDS 15 =416 ppm, ΔTDS 15 / 15=(428-416) / 15=0.8, A=17.496, therefore W=17.496×(0.8) -1 =21.87, H=21.87×(428-416)=262.4 ppm;

[0077] Location A, 2: TDS0 = 465 ppm, TDS 15 =445 ppm, ΔTDS 15 / 15=(465-445) / 15=4 / 3, A=18.047, therefore W=18.047×(4 / 3) -1 =13.535, H=13.535×(465-445)=270.7 ppm;

[0078] Location B1: TDS0 = 435 ppm, TDS 15 =416 ppm, ΔTDS 15 / 15=(435-416) / 15=1.267, A=17.146, therefore W=17.146×(1.267) -1 =13.536, H=13.536×(435-416)=257.2 ppm;

[0079] Location B2: TDS0 = 466 ppm, TDS 15 =443 ppm, ΔTDS 15 / 15=(466-443) / 15=1.533, A=18.097, therefore W=18.097×(1.533) -1 =11.802, H=11.802×(466-443)=271.5 ppm;

[0080] Location B, 3: TDS0 = 485 ppm, TDS 15 =473 ppm, ΔTDS 15 / 15=(485-473) / 15=0.8, A=18.914, therefore W=18.914×(0.8) -1 =23.643, H=23.643×(485-473)=283.7 ppm.

[0081] Table 1 (Unit: ppm)

[0082]

[0083] Referring to Table 1, the water hardness calculated using the water hardness testing device based on this application (hereinafter referred to as the basic algorithm in Table 1) has an error of less than 5.5% compared with the measured water hardness obtained by the traditional titration method (multiple parallel measurements were conducted in various locations). This method has high accuracy.

[0084] The above examples are applicable when the ratio of the measured water hardness (calculated as CaCO3) to the measured total dissolved solids (TDS) is between 50% and 60%.

[0085] However, in many cases, the ratio of water hardness (calculated as CaCO3) to total dissolved solids (TDS) falls outside the 50%-60% range. Furthermore, the hardness of municipal tap water varies daily and seasonally, making it difficult to guarantee that the ratio falls within the 50%-60% range. Moreover, when a water softener is operating normally, the hardness of the softened water should theoretically be much lower than the aforementioned 50%-60% range. To address these issues, this invention also provides an advanced water hardness detection device that can detect water hardness online. The difference in the rate of change of TDS before and after multiple electrolysis processes of a water sample (denoted as Δ(ΔTDS)) is used. n The correlation between the water hardness (denoted as ΔH) and the electrolysis time (where n represents the electrolysis time) is used to calculate the floating water hardness. This floating hardness is then combined with the standard water hardness obtained from a basic water hardness testing device to finally determine the water hardness of the water to be tested. In this application, the device of this embodiment can be referred to as a high-order water hardness testing device.

[0086] The advanced water hardness testing device includes: an inlet system, an electrolysis system, a detection system, a drainage system, a voltage control module, and a calculation module. The structures and connections of the inlet system, electrolysis system, detection system, drainage system, and voltage control module are similar to those in other water hardness testing devices; please refer to the previous description, which will not be repeated here.

[0087] The difference lies in that the electrolysis system 40 performs two electrolysis treatments on the water to be tested, while the detection system 50 performs four TDS detection treatments on the water to be tested. Specifically, firstly, the detection system 50 measures the first TDS value of the water to be tested (at this time, there is no electrolysis and the electrode is not pre-activated); then, the electrolysis system 40 performs the first electrolysis treatment on the water to be tested; then, the detection system 50 measures the second TDS value of the water to be tested; after that, the voltage control module 70 applies a positive voltage to the electrode to pre-activate the electrode; then, the detection system 50 measures the third TDS value of the water to be tested; then, the electrolysis system 40 performs the second electrolysis treatment on the water to be tested; finally, the detection system 50 measures the fourth TDS value of the water to be tested.

[0088] Based on the TDS data obtained from the above detection, the calculation module 80 obtains the first electrolytic TDS change rate of the water to be tested according to the first TDS value and the second TDS value; obtains the second electrolytic TDS change rate of the water to be tested according to the third TDS value and the fourth TDS value; and obtains the difference between the change rates according to the first electrolytic TDS change rate and the second electrolytic TDS change rate.

[0089] Furthermore, the calculation module 80 determines the standard water hardness based on the pre-measured correlation between water hardness and the change rate of the second electrolysis TDS; determines the floating water hardness based on the pre-measured correlation between the water hardness and the difference between the change rates; and determines the water hardness of the water to be tested based on the standard water hardness and the floating water hardness.

[0090] In other embodiments of this application, the solenoid valves of the inlet system, the detection system, and the drainage system can also be replaced by small water pumps, stepper motor valves, etc., to control the on / off state of the inlet water flow. During raw water / soft water hardness testing, the power supply, on / off actions, voltage application / disconnection, TDS probe power supply, signal acquisition, and final water hardness calculation functions of all solenoid valves (including replaceable stepper motor valves and small water pumps) can all be implemented by the electronic control program integrated on the circuit board 90.

[0091] The following is combined Figure 12 This document describes the workflow of a high-level water hardness testing device in detail. For simplicity, this embodiment uses the measurement of TDS values ​​of water samples before and after two different electrolysis processes as an example. In this embodiment, the electrolysis time in the electrolysis chamber is 15 seconds. Extensive experiments have proven that a 15-second electrolysis time can accurately and quickly measure water hardness. The following explanation uses an electrolysis time of 15 seconds (n=15) as an example. (Reference) Figure 12 Specifically, it includes the following steps:

[0092] The first step is to open all solenoid valves (including the inlet solenoid valve, the detection system solenoid valve, and the drain system solenoid valve) to allow the water sample to be tested to flow completely through all passages and chambers, and to perform a flushing operation (for example, for 25 seconds) to prevent any impurities that may be present in the device from contaminating the test results.

[0093] The second step is to fully rinse the sample and then close the solenoid valves of the detection system and drainage system to allow the water sample to fill the electrolysis chamber (time 2 is, for example, 5 seconds).

[0094] The third step is to apply a reverse voltage (e.g., 12V) to the electrodes. At this time, the graphite rod is the cathode and the metal mesh tube is the anode, the purpose of which is to clean the electrode surface (time 3 is, for example, 30 seconds).

[0095] Fourth step: Open the solenoid valve of the detection system and the solenoid valve of the drainage system (close the solenoid valve of the water inlet system) to drain the wastewater generated in the third step (time 4 is, for example, 5 seconds).

[0096] Fifth step, repeat the first step, that is, open all solenoid valves to allow the water sample to be tested to flow completely through all passages and chambers, and perform a flushing operation (time 1, for example, 25 s) to prevent impurities that may exist in the device from contaminating the test results.

[0097] Step 6: Repeat step 2, that is, after rinsing thoroughly, close the solenoid valves of the detection system and drainage system to allow the water sample to be tested to fill and fill the electrolysis chamber (time 2 is, for example, 5 seconds).

[0098] Step 7: Open the solenoid valve of the detection system to collect water into the detection chamber until the preset volume is reached (time 6, for example, 4 seconds).

[0099] Step 8: Close all solenoid valves, energize the TDS probe and collect TDS data, which is recorded as TDS. 0,1 (Time 7, for example, 30 seconds).

[0100] Step 9: Open the solenoid valves of the water inlet system and the water outlet system. While replenishing water to the electrolysis chamber, drain the water sample from the detection chamber (time 2 is, for example, 4 seconds).

[0101] Step 10: After the electrolysis chamber is filled, apply a positive electrolysis voltage to the electrodes to electrolyze the water to be tested (electrolysis voltage, for example, 12V, time, for example, 15 seconds).

[0102] Step 11: Repeat step 7, that is, open the solenoid valve of the detection system to collect water into the detection chamber until the preset volume is reached (time 6, for example, 4 seconds).

[0103] Step 12: Close all solenoid valves. The TDS probe is energized and begins collecting TDS data, denoted as TDS. 15,1 (Time 7 is, for example, 30 seconds).

[0104] Starting from step thirteen, repeat the basic process, that is... Figure 7 The process shown is not repeated here. The obtained TDS signal is denoted as TDS. 0,2 and TDS 15,2 .

[0105] Similarly, the duration of each operation in the above process, such as the polarity reversal or electrolysis voltage and the TDS probe detection time, are typical values ​​of this invention. In reality, different electrolysis chamber volumes and shapes will result in different filling times for the electrolysis chamber and detection chamber; different electrode configurations will also lead to different electrolysis voltages and electrolysis times; and different requirements for TDS signal accuracy will result in different TDS signal collection times. Therefore, it is not necessary to be limited to the operating parameters such as electrolysis voltage and solenoid valve on / off time mentioned in the above process; adjustments can be made according to the specific detection device.

[0106] In this embodiment, the following is defined:

[0107] ΔTDS 15,1 / 15=(ΔTDS 0,1 -ΔTDS 15,1) / 15, which is the TDS change rate of the first electrolysis.

[0108] ΔTDS 15,2 / 15=(ΔTDS 0,2 -ΔTDS 15,2 ) / 15, which is the change rate of TDS in the second electrolysis.

[0109] Δ(ΔTDS 15 / 15)=ΔTDS 15,2 / 15-ΔTDS 15,1 / 15, which is the difference in the rate of change.

[0110] refer to Figure 13 Based on the measurements of a large number of water samples, it can be seen that Δ(ΔTDS) 15 / 15) It exhibits a linear relationship with ΔH:

[0111] Δ(ΔTDS 15 / 15)= a'×ΔH-b'

[0112] Among them, when TDS0 varies within the range of 100-700 ppm, the standard water hardness (H) 标准 When the concentration varies within the range of 50-460 ppm, a' takes values ​​between -0.001 and -0.008, and b' takes values ​​between 0.1 and 1.2. Similarly, due to Δ(ΔTDS) 15 / 15) corresponds to the water hardness fluctuation value. When calculating water hardness, it should be calculated according to the following formula:

[0113] H = ΔH + H 标准

[0114] Where ΔH is based on Δ(ΔTDS) 15 / 15) corresponds to the floating value, H 标准 It is the standard hardness value set when measuring the curve.

[0115] refer to Figure 14 For municipal tap water in areas C, D1, D2, and E, three methods were used for actual measurement. The left column represents the actual value measured by titration, the middle column represents the hardness value obtained by a basic water hardness testing device, and the right column represents the hardness value obtained by a high-level water hardness testing device.

[0116] The high-order water hardness detection device of the present invention is used to calculate the hardness of municipal tap water. The specific calculation process is as follows:

[0117] Location C: TDS0 = 451 ppm, TDS 15 =444 ppm, ΔTDS 15 / 15=(451-444) / 15=7 / 15, A=18.932, therefore W=17.496×(0.8) -1 =40.57, H 标准 =40.57×(451-444)= 284.00 ppm. The difference in the rate of change Δ(ΔTDS) obtained after the second round of electrolysis. 15,1 / 15)=-1 / 3. With a=-0.0026 and b=0.2910, ΔH=16.28 ppm, and ultimately H=H 标准 +ΔH=284.00+15.96 ppm=299.96 ppm.

[0118] D location 1: TDS0 = 480 ppm, TDS 15 =473 ppm, ΔTDS 15 / 15=(480-473) / 15=7 / 15, A=18.914, therefore W=18.914×(7 / 15) -1 =40.530, H 标准 =40.53×(480-473)=283.71 ppm. The difference in the rate of change Δ(ΔTDS) obtained after the second round of electrolysis. 15,1 / 15)=-1 / 3. With a=-0.00247 and b=0.271, ΔH=24.923ppm, and ultimately H=H 标准 +ΔH=283.71+25.21=308.92 ppm.

[0119] D area 2: TDS0 = 482 ppm, TDS 15 =475 ppm, ΔTDS 15 / 15=(482-475) / 15=7 / 15, A=18.914, therefore W=18.914×(7 / 15)-1=40.530, H 标准 =40.53×(482-475)=283.71 ppm. After a second round of electrolysis, the difference in the rate of change is -0.4. With a=-0.00248 and b=0.271, ΔH=51.89 ppm, and finally H=H 标准 +ΔH=283.71+51.89=335.60 ppm.

[0120] Location E: TDS0 = 479 ppm, TDS 15 =463 ppm, ΔTDS15 / 15=(479-463) / 15=16 / 15, A=18.619, therefore W=18.619×(16 / 15) -1 =17.455, H标准 =17.455×(479-463)=279.28 ppm. After a second round of electrolysis, the difference in the rate of change is obtained as Δ(ΔTDS). 15,1 / 15)=-1. With a=-0.0026 and b=0.271, ΔH=280.2ppm, and ultimately H=H 标准 +ΔH=279.28+280.2 ppm=559.48 ppm.

[0121] Table 2 (Unit: ppm)

[0122]

[0123] Referring to Table 2, a comparison shows that the water hardness calculated using the basic water hardness testing device (referred to as the basic algorithm in Table 1) and the advanced water hardness testing device (referred to as the advanced algorithm in Table 1) of this application is more accurate than the measured water hardness values ​​obtained by the traditional titration method (multiple parallel measurements were conducted in various locations).

[0124] Although this disclosure has been described in detail with reference to specific embodiments thereof, those skilled in the art will understand that various changes and modifications may be made therein without departing from the spirit and scope of the embodiments. Therefore, this disclosure is intended to cover modifications and variations thereof, and any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of the claims of this disclosure and their equivalents.

[0125] Furthermore, features disclosed in the foregoing description, claims, or drawings, expressed in their particular form or according to the manner of performing the disclosed functions or the method or process for obtaining the disclosed results, may, as appropriate, be used alone or in any combination of these features to implement the invention in their different forms. Specifically, one or more features of any embodiment described herein may be combined with one or more features of any other embodiment described herein.

[0126] Protection may also be sought for any features disclosed in any one or more public documents combined with this disclosure and / or merged by reference.

Claims

1. A water hardness testing device, characterized in that, include: An electrolysis system includes a sealed electrolysis chamber, one end of which is provided with a limiter for fixing an anode, and the other end of which is provided with a base for fixing a cathode, wherein the cathode is arranged around the anode, and an electrode separator is provided between the cathode and the anode. The detection system includes a detection chamber in fluid communication with the electrolysis system, and the detection chamber has a TDS probe for detecting the TDS value of the water to be tested in the detection chamber; Specifically, before the electrolysis system electrolyzes the water to be tested, the detection system performs a first measurement to obtain the TDS value of the water to be tested before electrolysis; after the electrolysis system electrolyzes the water to be tested, the detection system performs a second measurement to obtain the TDS value of the water to be tested after electrolysis. The calculation module calculates the electrolysis TDS change rate based on the TDS values ​​of the water before and after electrolysis, and determines the water hardness of the water to be tested based on the pre-determined correlation between water hardness and the electrolysis TDS change rate.

2. A water hardness testing device, characterized in that, include: An electrolysis system includes a sealed electrolysis chamber, one end of which is provided with a limiter for fixing an anode, and the other end of which is provided with a base for fixing a cathode, wherein the cathode is arranged around the anode, and an electrode separator is provided between the cathode and the anode. The detection system includes a detection chamber in fluid communication with the electrolysis system, and the detection chamber has a TDS probe for detecting the TDS value of the water to be tested in the detection chamber; The voltage control module applies a positive voltage to the electrodes to pre-activate them; The electrolysis system performs a first electrolysis treatment on the water to be tested before pre-activating the electrode, and a second electrolysis treatment on the water to be tested after pre-activating the electrode; the detection system performs a first measurement on the water to be tested to obtain a first TDS value before the first electrolysis treatment, a second measurement on the water to be tested to obtain a second TDS value after the first electrolysis treatment, a third measurement on the water to be tested to obtain a third TDS value before the second electrolysis treatment, and a fourth measurement on the water to be tested to obtain a fourth TDS value after the second electrolysis treatment. The calculation module obtains the first electrolytic TDS change rate of the water to be tested based on the first TDS value and the second TDS value; obtains the second electrolytic TDS change rate of the water to be tested based on the third TDS value and the fourth TDS value; and obtains the difference between the change rates based on the first electrolytic TDS change rate and the second electrolytic TDS change rate. The calculation module further determines the standard water hardness based on the pre-measured correlation between water hardness and the change rate of TDS in the second electrolysis; determines the floating water hardness based on the pre-measured correlation between the difference between water hardness and the change rate; and determines the water hardness of the water to be tested based on the standard water hardness and the floating water hardness.

3. The apparatus according to claim 1 or 2, characterized in that, Also includes: The water inlet system is connected to the water softener at its inlet end and to the electrolysis system at its outlet end. A drainage system is provided, which is in fluid communication with the outlet of the detection system.

4. The apparatus according to claim 3, characterized in that, The water inlet system, the electrolysis system, the detection system, and the drainage system are arranged sequentially from top to bottom.

5. The apparatus according to claim 1 or 2, characterized in that, The electrolysis chamber is a cylindrical structure that extends along the axial direction.

6. The apparatus according to claim 1 or 2, characterized in that, The electrolysis system also includes an overflow channel disposed above the electrolysis chamber.

7. The apparatus according to claim 1 or 2, characterized in that, The inner wall of the electrolysis chamber has a draft angle.

8. The apparatus according to claim 1 or 2, characterized in that, The voltage control module is also used to apply a reverse voltage to clean the electrodes.

9. The apparatus according to claim 1 or 2, characterized in that, Also includes: The detection system measures the correlation between the rate of change of water hardness and the electrolytic TDS of water by changing the pH value of the water while keeping the water hardness and TDS constant.

10. The apparatus according to claim 1, characterized in that, Also includes: A voltage control module is used to apply a positive voltage to the electrode to preactivate the electrode.

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